Airfoil stall - When bubble burst vs. When lift drops?
 

Hi,

I've been simulating a very thin airfoil in Low-Reynolds number flow. I've always though that the lift would drop when the separation bubble burst at the suction side of the airfoil, resulting in stall.

Lift:
The result show linear growth in Lift up to angle of 6° when the lifting slope increases up to angle of 10° when the lift drops.

Laminar Separation Bubble
When investigating the laminar separation bubbles, the bubble on suction sides seems to burst at angle of 6° or 7°.

Drag
As the laminar separation bubble increases, the drag is increased allot as expected. Drag starts growing allot at 5° or 6°

Lift / Drag
The maximum Lift / Drag is around 5° or 6°.

So... does the airfoil stall around 6° or 10° ?